tmapsd

[f, Syy, Hm0, fp, Tp, Tm01, Tm02, PHI] = tmapsd(U10, F, h, fp, fs, N, CalSpectralSP, transfCalcMethod, kCalcMethod, dispout)

Description

Calculate TMA spectrum (power spectral density), (Bouws et al. 1985)

Inputs

U10=10;

Wind velocity at 10 meter above surface level in (m/s)

F=10000;

Wind fetch length in (m)

h=5;

Mean water depth in (m)

fp=0.33;

Peak wave frequency (fp=1/Tp) in (Hz)

If CalSpectralSP=’yes’; then fp is calculated from U10 and F

fs=2;

Sampling frequency that data collected at in (Hz)

N=256;

Total number of points between 0 and fs that spectrum reports at is (N+1)

CalSpectralSP=’yes’;

Define to calculate spectral shape parameters or not (‘yes’: calculate, ‘no’: use given parameters by user)

transfCalcMethod=’approx’;

Transformation function from JONSWAP into TMA calculation method

‘approx’: approximated method, ‘tucker’: Tucker (1994), ‘kitaigordskii’: Kitaigordskii et al. (1975)

kCalcMethod=’beji’;

Wave number calculation method

‘hunt’: Hunt (1979), ‘beji’: Beji (2013), ‘vatankhah’: Vatankhah and Aghashariatmadari (2013)

‘goda’: Goda (2010), ‘exact’: calculate exact value

dispout=’no’;

Define to display outputs or not (‘yes’: display, ‘no’: not display)

Outputs

f

Frequency (Hz)

Syy

Wave Energy Power Spectrum (m^2/Hz)

Hm0

Zero-Moment Wave Height (m)

fp

Peak wave frequency (Hz)

Tp

Peak wave period (second)

Tm01

Wave Period from m01 (second), Mean Wave Period

Tm02

Wave Period from m02 (second), Mean Zero Crossing Period

PHI

Transformation function from JONSWAP into TMA

Examples

[f,Syy,Hm0,fp,Tp,Tm01,Tm02,PHI]=tmapsd(10,10000,5,0.33,2,256,'yes','approx','beji','yes');

References

Beji, S. (2013). Improved explicit approximation of linear dispersion relationship for gravity waves. Coastal Engineering, 73, 11-12.

Bouws, E.; Günther, H.; Rosenthal, W., and Vincent, C.L., (1985). Similarity of the wind wave spectrum in finite depth water: 1. Spectral form. Journal of Geophysical Research: Oceans, 90(C1), 975-986.

Goda, Y. (2010). Random seas and design of maritime structures. World scientific.

Hunt, J. N. (1979). Direct solution of wave dispersion equation. Journal of the Waterway Port Coastal and Ocean Division, 105(4), 457-459.

Kitaigordskii, S. A., Krasitskii, V. P., & Zaslavskii, M. M. (1975). On Phillips’ theory of equilibrium range in the spectra of wind-generated gravity waves. Journal of Physical Oceanography, 5(3), 410-420.

Vatankhah, A. R., & Aghashariatmadari, Z. (2013). Improved explicit approximation of linear dispersion relationship for gravity waves: A discussion. Coastal engineering, 78, 21-22.

Tucker, M. J. (1994). Nearshore waveheight during storms. Coastal Engineering, 24(1-2), 111-136.